too large png images

[Horizon]

The image upload routine works great and efficiently for jpg images.

Good test - jpg works great, as expected with jpg quality set default 70.
If a user upload a large jpg file, the system saves the thumbnail and large sizes, and resizes the original to 2x large and saves as a jpg.
JPG Test: upload jpg of 6000x4000 pixels 7.5 MB. System saves

.jpg thumbnail 200 pixels 5 KB
_x2.jpg 400 pixels 20 KB
_large.jpg 1200 pixels 133 KB
_orig.jpg 2400 pixels wide. 696 KB

OK.


Bad test - pngs sometimes are very unoptimized:
If a user uploads a large png file, the system saves an _orig.png that is also extremely large, and sometimes doesn't seem to resize it.
RGB PNG Test1: upload png rgb 6000x4000 pixels 17.1 MB. System saves _orig.png which is 17.1 MB and not resized.

.jpg thumbnail 200 pixels 51KB
_x2.jpg 400 pixels 232 KB
_large.jpg 1200 pixels 1.5 MB
_orig.jpg 6000 pixels 17.1 MB

Problem: _orig.png not optimized at all, and both jpg thumbnail and large image excessively large (10x file size compared to jpg input original) slowing down page.



RGB PNG Test2: upload png rgb 3500x2332 pixels 7.6 MB. System saves _orig png which is 5.2 MB resized to 2400 pixels wide. Also very unoptimized.

.jpg thumbnail 200 pixels 55KB
_x2.jpg 400 pixels 224KB
_large.jpg 1200 pixels 1.5 MB
_orig.jpg 2400 pixels 5.2MB

Problem: _orig.png not optimized well, and both jpg thumbnail and large image excessively large slowing down page.